Problem: $ A = \left[\begin{array}{rr}6 & 9 \\ 1 & 4\end{array}\right]$ What is $ A^{T}$ ?
To find the transpose, swap the rows and columns. $ A^{T}$ = $\left[\begin{array}{rr}6 & 1 \\ 9 & 4\end{array}\right]$